April 17, 2022
Do you guys still remember how to use plant hormones in I/GCSE Biology?
Selective weed killers
- In I/GCSE Biology, Two ways to kills weeds
- Pull out each weed by hand
- Spray lawn with selective weed killers
- Most common weed killer – 2,4-D
- 2,4-D = similar structure to auxins, has greater effect
- Absorbed by broad-leaved plants – accumulates in stem + root tips = causes uncontrolled growth
- Plant dies, 2,4-D not absorbed by narrow-leaved plants e.g. grass
Agent Orange
- Caused leaves to fall off in jungle
- Significant increase of children born with birth defects
- In I/GCSE Biology, Also causes diseases
Rooting powders
In I/GCSE Biology,
- Cutting used to produce large numbers of identical plants
- Part of plant is cut off and stem is dipped in rooting powder
- End of stem then placed in compost
- Roots develop from cut stem
- Rooting powders contain auxins = stimulate the stem cells to develop into roots
Ripening fruit
- In I/GCSE Biology, Gas ethane (ethylene) = plant hormone
- Produced by fruits as they ripen
- Stimulate reactions = convert starch into sugar
That's all~